Scaffold-suspension device



Aug. 20, 1929. A, c, FISCHER 1,725,183

SGAFFOLD SUSPENS ION DEVICE Filed Aug. 23, 1926 2 Sheets-Sheet l 2 Sheets-Sheet 2 A. C. FISCHER SCAFFOLD SUSPENSI EON DEVICE Filed Aug. 23, 1926 Patented Aug. 20, 1929.

UNITED STATES ANTHONY C. FISCHER, OF CHICAGO, ILLINOIS.

SCAFFOLD-SUSPENSION DEVICE.

Application filed August 23, 1926.

The invention relates to scaffold suspension devices.

In the use of machines set forth in Letters Patent of the United States No. 1,114,832,

dated October 27, 1914, it has been found to be desirable to form the clutch boxes Or cases of wrought metal parts to render them more secure against breakage, in lieu of castings, and one object of the invention is to provide an improved clutch box which may be built up of wrought metal parts. It has also been found that when the clutches are housel so that they are invisible, the operator cannot detect their inoperativeness, and, therefore, it

has been found advantageous to provide a structure which renders the clutches visible, so that the operator may readily detect any failure of the clutches to grip the cable when it is intended that they should.

Another object of the invent-ion is to provide a construction in which the clutches are sufiiciently visible to enable the operator to detect any failure to grip the suspension cable.

Another object of the invention is to provide improved clutch-releasing means which is carried by the clutch box.

Another object of the invention is to provide an improved platform supporting bar which may be readily and safely attached to the lifting device and removed therefrom.

The invention consists in the several novel features hereinafter set forth and more particularly defined by claims at the conclusion hereof.

In the drawings: Fig. 1. is a perspective of a scaffold and suspension devices therefor embodying the invention. Fig. 1 is a detail perspective of a pair of top-bars of the roof-support. Fig. 1" is a perspective of one of the roof-supporting standards. Fig. 2 is a side elevation of one of the suspension devices. Fig. 8 is a vertical section of one of said devices on a somewhat larger scale.

Fig. 4 is a section taken on line 4% of Fig. 8. Fig. 5 is a section taken on line 55 of Fig. 2. Fig. 6 is a perspective of one of the platform supporting bars. Fig. 7 is a perspective of the upper portion of one of the clutch boxes.

The invention is exemplified in connection with steel Outriggers 10 which have their inner ends suitably secured, usually by U-bolts from the framework of the building in the Course of erection and their outer ends pro- Serial No. 130,804.

jecting beyond the face of the building. Each outrigger supports a pairof cables 11 which have their upper ends 12 looped around the outrigger and are adapted to serve as suspension cables for supporting a vertically movable platform 13. This platform is adapted to support workmen in applying facing to or performing other work on the structure. To support the platform from the suspension cables at different elevations and to raise and lower the platform in the course of work, the platform is supported by underlying crosshars 1+1 each of which is supported from the pair of cables 11 by means of a lifting de ice. These lifting devices are of the same construction, so that a description of one will apply to all.

Each of these lifting devices comprises a pair of vertical rods 15 which are rigidly secured together and in spaced relation by bars 16 which are secured to the rods 15 respectively between upper nuts 17 and lower nuts 18. Each of these lifting devices comprises a cable gripping mechanism carried in a box 19 which is fixedly secured to the rods 15 and a gripping mechanism enclosed in a box 20 which is slidably mounted on rods 15, so that the lifting device may he raised or lowered along the cable to correspondingly shift the platform 13 by shifting one of the gripping devices vertically while the other is clamped to the cable. Each of these boxes 19, 20, is composed of a heavy bottom bar 21, and a similar bar 22, which are provided with holes through which the rods 15 extend vertically and sheet metal side plates 23 and 24 Which are similar in shape and extend between the bars 21 and 22 with their side edges terminating approximately at the inner edges of the rods 15. These plates are secured to said bars by screws 24, so that the bars and plates will form a box ing or housing for the gripping devices hereinafter set forth. Centrally, the plates 23 are secured in spaced relation by rivets 26. These rivets prevent the plates from spreading between the bars 21 and 22. Box 19 is fixedly secured to and against longitudinal movement relatively to rods 15 by collars 27 which engage the lower cross-bar 21 of the box and by nuts 28 which are threaded to the upper ends of said rods and engage the top bar 22 of said box. Bars 21 and 22 of box 20 are free to slide on the rods 15 relatively to the box 19 when the gripping device in the box 20 is released from cable 11, and box 19 is free to slide with rods relatively to box when the latter is locked to the cable and the gripping device in box 19 has been released.

The gripping devices in boxes 19 and 20 respectively each comprise a pair of aws and 31 which are longitudinally grooved to receive and grip opposite peripheral portionsof the cable 11, and are connected for conjoint vertical movement by lugs 32 integrally formed with one of the jaws and extending into recesses 33 in the sides of the companion aw. Each aw is provided with upper and lower wedge or cam faces 34 and 35, each of which is adapted to ride against the periphery of a roller 36. Each roller 36 is carried by a stud 36 which extends through the side plates 23 and 24. Each jaw is pressed upwardly by a spring 37 to force the wedge surfaces upwardly, so that the jaws will be forced into gripping engagement with the cable 11.

Each spring 37 has its upper end extend-ed around a pin 38 fixed in a laterally projecting lug 39 on one of the jaws and its lower end extended longitudinally into a recess 40 formed in the top of a bar 22. Normally, the

gripping devices in both the boxes 19 and 20 are pressed in position to grip the cable by springs 37 and the wedge surfaces, so that the gripping devices will at all times, except when they are manually released, be effective to secure the lifting device against vertical movement to the cable.

For imparting and controlling vertical movement of the boxes 19 and 20 and the gripping devices carried thereby respective- ].y, a lever 41 is provided, composed of bars pivoted by a bolt 42, which extends through side plates 23 and 24 and the bottom bar 21, to box 19. The bars forming lever 41 have their inner ends disposed at the side of the box plates and their outer ends brought into abutting relation and secured together by rivet 43. Lever 41 is connected to the box 20 by links 44 which have their lower ends pivoted to said box by bolts 45 which extend through the side plates and top bar 22 of said box. The upper ends of said links are pivoted to lever 42 by bolts 46. If desired, an extension bar (not shown) may be used to operate the lever 41. By means of this lever and link, which are pivoted together and to the boxes respectively, lever 41 will raise or lower box 19, rods 15 and the platform 13 when the box 20 is locked to the cable and the gripping device in box 19 is free. When the box 19 is locked to the cable and the box 20 is free, lever 14 may be raised or lowered to correspondingly shift box 20 to bring said box into position to permit the box 19 to be moved another step in the desired direction. By alternatingly releasing and shifting the boxes through the medium of lever 41, the entire lifting device may be stepped upwardly or downwardly along the cable 11 to bring the platform 13 into the desired elevation.

In the shifting of the boxes it is necessary to release the gripping jaws, and for this purpose a lever is pivoted by a bolt 51, extending through side plates 23, 24 to each of the boxes. A bolt 52 extends through the inner end of lever 50. Said lever is composed of a pair of bars, the inner ends of which are separated, and the outer ends joined together. Each of the gripping jaws is provided at its upper end with a laterally pro-- j ecting lug 53 and bolt 52 is adapted to abut against the upper face of one of these lugs to force the jaws downwardly against the force of springs 37 and into position so the wedges 34 will permit the jaws to release the cable 11. Each of the side plates 23, 24 is formed with an opening 55 through which the bolt 52 extends and through which the upper ends of the jaws and lugs 53 will be visible at all times. As a result, if, for some unknown cause, the jaws should not, while the lifting device is at rest, be in its lowered or gripping position, the operator can discern that condition, because the upper ends of the jaws are visible through said openings.

Levers 50, while they are not attached to the gripping jaws, remain pivotally connected at all times to the boxes, so that they are always in readiness to be operated when desired to release the gripping devices respectively. These levers 5O exemplify devices by which the gripping device in one of the boxes may be released while the lever 41 is being operated, to vertically shift the boxes containing the other gripping device.

In practice, it is desirable to readily as semble and disassemble the parts, and for the purpose of making it possible to readily place the cross-bars 14 into and out of connected relation with the lifting devices, each of said cross-bars is formed of a pair of angle-iron strips 14*, the vertical flanges of which are fixedly secured together by bolts 14 and sleeves 14 which fix them in properly spaced relation. The outwardly extending horizontal flanges of said angle irons are notched as at 14 to receive and straddle the rods 15 respectively. 'As a result these crossba-rs may be tilted and inserted lengthwise between the rods 15 and then swung into position so the horizontal flanges will rest on nuts 17. When so inserted, the cross-bars will be securely held against ondwise and crosswise displacement. To remove the bars, it is only necessary to reverse the placement operation.

In practice, it is also desirable to provide overhead protection for the workmen on the platform. To support a roofing of boards so it will be raised and lowered with the platform 13 by the lifting devices, uprights 61, the lower ends of which are adapted to rest on the top of bars 22 of the upper boxes 19 respectively, are provided with eyes 62 through which the cables 11 extend to hold the uprights alongside of the cables. The upper ends of uprights 61 are provided with open ended slots 63 to receive bolts 64. Top bars, composed of strips 65, are adapted to be secured to the upper ends of the uprights by said bolts. Strips 65 are provided with perforations 66, so that they may be extended according to different spacings between the cables. Bolts 64 and slots 63 permit the strips to be readily connected to and disconnected from the uprights 61 in assembling and disassembling the equipment.

The invention exemplifies scaffold suspension devices, in which the boxes for the cable gripping devices are made up of wrought metal parts; in which the releasing levers are .pivotally mounted on the boxes containing the gripping devices so as to be conveniently available at all times to effect the release of said devices; in which the boxes containing the gripping devices are provided with side openings which permit the operators to readily discern when one of the gripping devices fails to grip the cable; and in which the platform supporting bars may be readily connected to and removed from the lifting devices.

The invention is not to be understood as restricted to the details set forth, since these may be modified within the scope of the appended claims, without departing from the spirit and scope of the invention.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent, is:

1. In scaffold suspension devices, the combination of a pair of rods, a pair of automatic clutches adapted to grip a suspension cable and comprising jaws and members for shifting the jaws into engagement with the cable, boxes containing the clutches respectively, one of which is rigidly secured to the rods, and the other of which is slidable thereon, said boxes being formed of upper and lower cross bars through which the rods are extended and sheet metal side plates fixed to the bars and operative to house the clutches and support the aforesaid members, and means for relatively shifting the boxes to raise or lower them along the cable.

2. In scaffold suspension devices, the combination of a pair of rods, a pair of automatic clutches adapted to grip a suspension cable and comprising aws and members for shifting the jaws into engagement with the cable, boxes containing the clutches respectively, one of which is rigidly secured to the rods, and the other of which is slidable thereon, said boxes being formed of upper and lower cross-bars through which the rods are extended and sheet metal side plates fixed to the bars and operative to house the clutches and support the aforesaid members, spacing elements securing the plates apart between the bars, and means for relatively shifting the boxes to raise or lower them along the cable.

3. In scaffold suspension devices, the combination of a pair of rods, a pair of automatic clutches, adapted to grip a suspension cable and comprising jaws and members for shifting the jaws into engagement with the cable, boxes containing the clutches respectively, one of which is rigidly secured to the rods, and the other of which is slidable thereon, said boxes being formed of upper and lower cross-bars through which the rods are extended and sheet metal side plates fixed to the bars and operative to house the clutches and to support the aforesaid members, said plates being provided with side openings through which the upper ends of the clutches are visible, and means for relatively shifting the boxes to raise or lower them along the cable.

4. In scaffold suspension devices, the combination of a pair of rods, a pair of automatic clutches, adapted to grip a suspension cable, boxes containing the clutches respectively, one of which is rigidly secured to the rods, and the other of which is slidable thereon, said boxes being formed of upper and lower cross-bars through which the rods are extended and sheet metal side plates fixed to the bars, said plates being provided with side openings through which the upper ends of the clutches are visible, releasing levers for the clutches provided with pins movable in said openings, and means for relatively shifting the boxes to raise or lower them along the cable.

5. In scaffold suspension devices, the combination of a pair of rods, a pair of automatic clutches adapted to grip a suspension cable, boxes containing the clutches respectively, one of which is rigidly secured to the .rods and the other of which is slidable thereon, means for relatively shifting the boxes to raise or lower them along a cable, and levers pivoted to and on the outside of the boxes and provided with means extending into said boxes and operative to engage the clutches to release them.

6. In scaffold suspension devices, the combination of a pair of rods, a pair of automatic clutches, adapted to grip a suspension cable, boxes containing the clutches respectively, one of which is rigidly secured to the rods, and the other of which is slidable thereon, said boxes being formed of upper and lower cross-bars through which the rods are extended and sheet metal side plates fixed to the bars, said plates being provided with side openings through which the upper ends of the clutches are visible, releasing levers straddling and pivoted to the side plates provided with pins extending through said openings, and means for relatively shifting the boxes to raise or lower them along the cable.

7. In scaffold suspension devices, the combination of a pair of lifting devices each comprising a pair of rods, a plurality of automatic clutches adapted to grip a suspension cable, boxes containing the clutches respectively, one of which is rigidly secured to the rods and the other of which is slidable. thereon, and means for relatively shifting the boxes to raise or lower them along the cable, and a roofing support comprising uprights adapted to be supported by said devices and provided with eyes through which the cables are extended and a crossbar between the upper ends of the uprights and bolt and slot connections between the bar and the uprights.

8. In scaffold suspension devices, the combination of a pair of lifting devices each comprising a pair of rods, a plurality of automatic clutches adapted to grip a suspension cable, boxes containing the clutches respectively, one of which is rigidly secured to the rods and the other of which is slidable thereon, and means for relatively shifting the boxes to raise or lower them along the cable, and a platform supporting bar composed of a pair of angle irons adapted to extend between the rods of the lifting devices and having horizontal flanges notched to straddle the rods of the lifting devices.

9. In scaffold suspension devices, the combination of a pair of lifting devices each comprising a pair of rods, a plurality of automatic clutches adapted to grip a suspension cable, boxes containing the clutches re-' spectively, one ofwhich is rigidly secured to the rods and the other of which is slidable thereon, and means for relatively shifting the boxes to raise or lower them along the cable, and a roofing support comprising uprights adapted to be supported by said devices and provided with eyes through which the cables are extended and a crossbar to extend between the upper ends of the uprights comprising a pair of strips extensively secured together, and bolt and slot connections between the ends of said strips and the uprights.

"Signed at Chicago, Illinois, this 29th day of July, 1926.

ANTHONY G. FISCHER. 

